body{
    margin: 0;
    padding: 0;
}

.sign-div{
    width: 100%;
    height: 100%;
    padding: 0px;
    text-align: center;
    /*flask中设置html背景图片必须放在static文件夹中*/
    background: url(../images/vaccine.jpg) no-repeat;
    position:absolute;
    background-size: cover;
    box-sizing: border-box;
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
    overflow: hidden;
}
.sign-div h1{
    margin-top: 100px;
    color: #fff;
    font-size: 40px;
}

.sign-div label {

    text-align: left;
    color: black;
    font-size:30px;
    font-family: 宋体;
    font-weight: bold;
    width: 200px;
}

.test {
    color: black;
    font-size: 20px;
}


.active {
    background-color: #4CAF50;
}

/*  悬浮按钮 */
.button {
    display: inline-block;
    border-radius: 44px;
    background: rgba(100,149,237,.7);
    color: aliceblue;
    border: none;
    text-align: center;
    font-size: 10px;
    padding: 20px;
    width: 150px;
    transition: 0.8s;
    cursor: pointer;
    margin-top: 50px;
    margin-bottom: 50px;
}
.button:hover {
    transform: scale(0.96);
}